﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace exerciseTwo
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("输入学生成绩： ");
            int number = int.Parse(Console.ReadLine());
            string temp;
            if (number < 60) 
            {
                temp = "1";
            }
            else
            {
                if (number<80)
                {
                    temp = "2";
                }
                else
                {
                    if (number<90)
                    {
                        temp = "3";
                    }
                    temp = "4";
                }
            }
            switch (temp)
            {
                case "1":
                    Console.WriteLine("成绩不及格");
                    break;
                case "2":
                    Console.WriteLine("成绩及格");
                    break;
                case "3":
                    Console.WriteLine("成绩良好");
                    break;
                case "4":
                    Console.WriteLine("成绩良好");
                    break;
            }
            Console.ReadKey();
        }
    }
}
